1. Field of the Invention
The present invention relates to swabs for collecting biologcal samples and more particularly concerns a swab having improved handle features and a swabbing tip made of closed cell foam.
2. Description of Related Information
Traditionally, testing for microorganisms such as Streptococcus has been performed by, for example, taking a sample from the patient's throat using a soft tipped swab in order to accumulate as large a sample of the suspected organism as reasonably possible. The organism was then placed in a culture medium and grown until sufficient quantities existed for identification. Swabs used to gather microorganism samples have been made of fibrous materials such as cotton, polyester and rayon, and open pore or open cell foam as taught by Sills in U.S. Pat. No. 3,724,018. The more microorganisms that could be collected the faster the colonies could be grown to sizes necessary to reach a conclusion regarding the presence of specific microorganisms. Accordingly, many swab designs and related accessories have been developed to assure a reasonable sample size and to protect the microorganisms in the time period between sampling and culturing. For example, U.S. Pat. No. 4,492,305 to Avery teaches a culture collection system which attempts to keep the culture alive for a period of time until it is tested. Avery teaches a culture collecting swab and a sealed glass ampoule with a resilient closure member positioned at the stem of the swab. After culture collection the ampoule is broken open, along a score line, and the tip end of the swab is inserted into the ampoule through the open end into culture sustaining media wherein further penetration causes the resilient closure to seal the opening thus defining a culture sustaining environment for the swab and the collected microorganisms until testing.
Although traditional testing and culture growth methods have evolved into more efficient systems there is still a substantial time delay between the specimen collection and the actual determination. When dealing with life threatening or serious health hazards these time delays still present impediments to timely diagnosis and treatment. Substantial improvements in health care have been achieved by newly developed improved testing procedures which result in a determination in hours and in sometimes minutes after sample collection. These short duration tests do not rely on the collection and growth of microorganisms but look to identify chemical characteristics of the suspected biological substance such as an antigen which is associated with, for example, Streptococcus. Tests along these lines seek only to gather portions of the Streptococci, the antigen, and expose this biological sample to an antibody which is known to attach itself to the specific antigen. Accordingly, if the antigen is present the antibody will attach to it and a determination may be made. The prior art has taught attaching radioisotopes to antibodies so that if the antibody attaches to the antigen there will be a concentration of radioactive material at the attaching sites. This type of testing is known as a technique of a radioimmunoassay (RIA). Obviously, unattached antibodies must be removed so that only the combined antibody-antigen groups will remain. Antibodies have also been coupled with fluorochromes which are responsive to light and to enzymes which can react with additional substances to produce color changes and more recently to liposomes which contain color dyes.
In U.S. Pat. No. 4,618,576, Rosenstein et al. teach a test that can be performed in less than seventy minutes to determine the presence of Group A Streptococcus. Rosenstein et al. teach the use of a fiber swab on the end of a stick for swabbing the infected area to collect antigen in its fibers. Subsequently, the swab is dipped in a solution of extraction reagent containing enzymes which facilitate the release of the Streptococcus A antigen from the swab. Finally, an indicator reagent is provided with antibodies that are specifically reactive to the Streptococcus A antigen.
As technology allows the development of tests that are faster, it is more important to take the sample and deliver it to the test site in a timely manner. It may no longer be practical to have a fibrous swab or a tip containing interconnected cavities which trap the biological specimen thus requiring time to extract it from the interior of the swab or special solutions to promote the removal of the biological substance from the swab. Faster tests may be complemented with improved swab structures which allow the effective collection of a biological sample and its rapid transfer to the test system.
Also, traditional swabs having cotton or other fiber tips on rigid rod like shaft portions made of wood or plastic present potential problems due to the underlying sharp edges on rigid shaft portions which may irritate or injure the collection area if the sample is not properly and carefully taken. This potential for irritation is fibrous tip of the swab to provide complete protection from the sharp edge of the rod like wood or plastic shaft. Also, the straight shaft structure is not necessarily designed to be anatomically correct with respect to the portion of the patient body wherein the sample is being taken or with respect to the sample taker's hand. Bennett in U.S. Pat. No. 3,871,375 provides an improved structure wherein the open cell tip and the shaft portion of the swab are molded in the same cavity so that the blended region joining the central shaft and the soft, resilient tip merges gradually from the low porosity more rigid shaft portion to the high porosity soft resilient tip so that there is no sharp ended "stick" presented to the patient's body.
Although the prior art has addressed improved apparatus and tests for the taking of biological samples and the subsequent transfer and testing of these samples there is still a need for a simple, straight-forward, reliable, easily fabricated swab for collection of biological samples which provides for easier removal of the biological sample from the swabbing tip and improved structure, with respect to human factors, to improve the ease of sample gathering while minimizing the potential for irritation to the patient.